The signatories are a who’s who of tech giants: Apple, Autodesk, Dropbox, eBay, Facebook, Google, Intel, Microsoft, Netflix, Spotify, Square, Twitter, and Uber. The inclusion of the latter signee dovetails nicely with the news that Travis Kalanick left Trump’s advisory council late last week.

Notably absent from the list: Amazon. Even SpaceX and Tesla are signatories to the amicus brief, despite Elon Musk’s somewhat warm relationship with the Trump administration. It turns out that Amazon supported the Washington state legal case that caused a judge to issue a restraining order to prevent enforcement of Trump’s executive order, but they apparently can’t sign onto this amicus brief, according to JP Mangalindan:

That’s because Seattle-based Amazon had already filed a declaration in the same case explaining how the ban negatively affects the e-commerce giant. Washington’s attorney general advised Amazon not to join the amicus brief since it’s a witness in the original lawsuit, according to a source familiar with the matter.

It turns out that Microsoft, also absent from the amicus brief, filed a declaration in the original case brought by Washington, as well.

Here’s the thing: Microsoft is not absent from the amicus brief — they’re right there on page 41, the sixtieth signee. I’ve reached out to Mangalindan to ask how that squares up.